1. Field of the Invention
The present invention relates to security for a collective building, i.e., a multi-unit building. More particularly, the present invention relates to a collective building having a high-security computer network system configured therein with an administration server for administrating entry to multiple units in the building and to the computer network system for ensuring security therein.
2. Description of the Related Art
An apartment house administration system has been developed in which a LAN (local area network) is configured by installing a line concentrator, such as a router or a hub, in the apartment house. According to the conventional apartment house administration system, each dwelling unit is made secure against other dwelling units in the apartment house and against the outside of the LAN by administrating the line concentrator provided in the apartment house by means of an administration server connected thereto via the Internet.
However, according to the conventional apartment house administration system, it is hard to keep the LAN secure against outsiders because the LAN is administrated by the administration server connected to the LAN through the Internet. Moreover, it is difficult for the administration server connected to the LAN through the Internet to maintain detailed administration of network devices used in the respective dwelling units.